ContiSport2, uneasy on the road even after balanced?

[Icecreamfoo]

Can any tire/wheel gurus out there help a fellow 330i owner diagnose this "problem" that I'm experiencing?

Bought 2 ContiSport 2s from tire rack 2 weeks ago for my Rear sport pkg wheels, and had them mounted/balanced at a tireshop in Santa Monica (good sized shop, seemed reputable and knowlegeable about what they do). Since day 1 running on these new Conti2 in the rear, i've been noticing this "uneasy" feel while driving on the freeway at cruising speed (above 65 mph). It's not exactly tramling, i know what that's like.

This unsettled feeling that I'm getting from the steering wheel, is almost like i have one, or multiple wheels spining at different directions. Feels somewhat like the car is wiggling left and right from time to time, that I have to spend extra effort to concentrat holding on to the steering wheel to keep the car going straight.

I've had the balance re-checked by the tireshop, was told they're fine. none of the wheels are bent. weights on the front wheels are intact, I even did a 4 wheel alignment. Everything checked out fine, yet 2 weeks into these new tires this feeling persists. Spoke with Gary and customer service rep, they are sympathetic to my situation and I still have time to return the tires, but I'd like to see if anyone has any suggestion to this. Any idea what could attribute to this weird road feel, or anyone with similar experience?

How are yall ContiSport 2 owners' experience so far? Thanks!

[The HACK]

:dunno: Sounds normal, especially if you've got wheels up front that doesn't match the wheels in the rear.

Next time buy all 4 and replace all 4 if you want to avoid this, or keep to the same brand/compound.

[WAM]

Check the tire pressures too, that may be the problem.

Overall, I have Conti Sport 2's on all 4 wheels and I think they are pretty good tires.

I noticed a sharper steering response compared to the AVS ES100's I had on before.

[Icecreamfoo]

WAM, i run 37 psi in the rear, which isnt that much higher than the factory recommendation i think.. guess i'll have to try diff pressure. thanks

Hack, can running different tires front and back possibly cause this? I still have the original Conti 1 from factory up front, which still has close to 50% tread left thats why I didnt bother to replace them. Do sports package owners replace all 4 tires at the same time? Do you, or does any other owners, think that the staggered set up ampilifed, or aggrevated, to this feel, perhaps caused by different tread design of the Conti 1 front/Conti 2 rear ?

[The HACK]

Hack, can running different tires front and back possibly cause this?
YES.

Keep in mind that the tread pattern and level of grip of the CSC IIs are SIGNIFICANTLY different than the OEM CSCs. Running different compounds front and back is sometimes okay but CAN have unexpected results.

[Gary@Tirerack]

YES.

Keep in mind that the tread pattern and level of grip of the CSC IIs are SIGNIFICANTLY different than the OEM CSCs. Running different compounds front and back is sometimes okay but CAN have unexpected results.

The contact 2 is a large improvement over the original Sport Contact in grip. The wandering your describing though could simply be from feeling a full tread depth tire on th rear verus a more worn set of fronts. If this doesn't go away after the release mold has worn off <100 miles or so> I'd replace the fronts with a matching tire to eliminate the issue.